20241122_3 Comparison

Nullish Coalescing Operator (??)

The ?? operator returns the first argument if it is not nullish (null or undefined).

Otherwise it returns the second argument.

ex)let name = null;
let text = "missing";
let result = name ?? text;  // result  ==  "missing"

 

The Optional Chaining Operator (?.)

The ?. operator returns undefined if an object is undefined or null

ex) // Create an object:
const car = {type:"Fiat", model:"500", color:"white"};
// Ask for car name:
document.getElementById("demo").innerHTML = car?.name;